The present invention relates to a rotor for synchronous motors, which includes a permanent ring magnet, and a hub provided with a rotor shaft, which is connected to the ring magnet.
It has been known to use rotors of this type in synchronous motors. Connection of the rotor hub with the ring magnet is generally accomplished by pressing the hub into the ring magnet, as a result of which pressures in the ring magnet acting in a radial direction give rise to tensile stresses therein, which, in turn, frequently result in tears.
From Swiss Pat. No. 524,912, as well as from British Patent 1,353,082 rotors are known, whose magnet carriers or hubs include holding portions, which are in form-locking or force-locking connection with the front sides of the permanent ring magnets. Due to different respective coefficients of expansion of the magnet material and of the carrier material, tensile stresses in the ring magnet, and tears resulting therefrom can still not be avoided in the aforesaid constructions.